Home > Bike Types > Mountain Bike

Wytze van Mansum Concept Ultralight Carbon Alloy Bicycle Stem

Support us! Bikerumor may earn a small commission from affiliate links in this article. Learn More


Sure, this is just a prototype we pulled from his PDF portfolio, but after seeing what he did for Cannondale (The Dutchess commuter, link here) as part of a graduation project, we had to show you some more of his concepts.  Actually, the majority of the concept projects in Wytze van Mansum’s portfolio are bicycle related and totally worth checking out.

This bad boy is the Lightweight Stem for Road or Mountain Bike, and here’s what he had to say about it:

This idea originated from the fact that a lot of stems on the market tend to crush the thin carbon wrapped handlebars; these stems act as bench vices. In my search for a way of clapming the handlebar without squeezing them, I came up with a carbon strap around an aluminum center that still allows the user to take of the handlebards without having the take off the shifters, brakes and grips. I also wanted to use the materials in a way that makes sense.  Many stems out there have fance carbon looks, but they don’t use the strengths of the material to its best.

In this design I detached the different forces acting in a stem. The carbon is only put under tensile forces, and the aluminum only has to cope with the pressure forces and the torque. Because every part is only put under one type of force, the stem can be ultra lightweight.

More pics after the break…


Now if he just drilled out that top cap, it would really save some weight.


Notify of

This site uses Akismet to reduce spam. Learn how your comment data is processed.

Newest Most Voted
Inline Feedbacks
View all comments
14 years ago

Hey, this concept is cool ! We need some folks who re-think parts like this guy : that’s real innovation (even if it’s prospective design), go on like this Wytze.

By the way, Wytze is very close to the German word for “jokes” 😉

14 years ago

That is the risk of a public portfolio 😉

I had a go at making this and I found out there is one flaw:
As it is depicted here it does not have enough clamp power
at the headtube.

The carbon belt should go round the headtube again; ‘strangling’
the headtube. Actually this even simplifies the whole carbon wrap;
it becomes an continuous loop. (hard to explain, I should make a
new render)

If anyone wants to have a go at producing it, go ahead it is not
patented. And I would be glad to help out. Just creative comments
and a few samples 😉 Contact me!


I like your inovative thinking its like a reverse odyssey “elementary” and if you want some one to take your idea and patent it I sugest g french as he did it to me but don’t expect recognition or a sample still the other ideas I have will be patented I sugest you do the same I like the colour r.e.d

Subscribe Now

Sign up to receive BikeRumor content direct to your inbox.

Subscribe Now

Sign up to receive BikeRumor content direct to your inbox.